. >> reporter: the vice president and ryan clashed over the economy, taxes and medicare with the democrat often on the attack. >> and they're holding hostage the middle class tax cut. it's about time they take some responsibility. >> reporter: but ryan fired back. he slammed the obama administration's economic record. >> this is not what a real recovery looks like. we need real reforms for a real recovery and that's exactly what mitt romney and i are proposing. >> reporter: after several heated exchanges ryan insinuated that president obama's performance last week was motivating the vice president's -- >> i know you're under a lot of duress for making up for a loss round. >> reporter: who won? it depends who you ask. polls are mixed. in a cbs news poll of uncommitted voters, 50% thought the vice president run, 31% sided for ryan and 19% called it a tie. 56% thought biden would be an effective president if necessary compared with 49% for ryan. not surprisingly, both sides claimed victory. mitt romney's campaign said biden seemed off balance and strange. the president's team said the debate